Buggy code:
public class CompletionJavadocParser extends JavadocParser { public static final int INLINE_ALL_TAGS_LENGTH ; public static final int BLOCK_ALL_TAGS_LENGTH ; char [ ] [ ] [ ] levelTags = new char [ 2 ] [ ] [ ] ; int [ ] levelTagsLength = new int [ 2 ] ; int cursorLocation ; CompletionOnJavadoc completionNode = null ; boolean pushText = false ; boolean allPossibleTags = false ; public CompletionJavadocParser ( CompletionParser sourceParser ) { } public boolean checkDeprecation ( int commentPtr ) { } protected boolean commentParse ( ) { } protected Object createArgumentReference ( char [ ] name , int dim , boolean isVarargs , Object typeRef , long [ ] dimPositions , long argNamePos ) throws InvalidInputException { } protected Object createFieldReference ( Object receiver ) throws InvalidInputException { } protected Object createMethodReference ( Object receiver , List arguments ) throws InvalidInputException { } protected Object createTypeReference ( int primitiveToken ) { } private char [ ] [ ] [ ] possibleTags ( char [ ] prefix , boolean newLine ) { char [ ] [ ] [ ] possibleTags = new char [ 2 ] [ ] [ ] ; if ( newLine ) { System . arraycopy ( this . levelTags [ JavadocTagConstants . BLOCK_IDX ] , 0 , ( possibleTags [ JavadocTagConstants . BLOCK_IDX ] = new char [ this . levelTagsLength [ JavadocTagConstants . BLOCK_IDX ] ] [ ] ) , 0 , this . levelTagsLength [ JavadocTagConstants . BLOCK_IDX ] ) ; } else { possibleTags [ JavadocTagConstants . BLOCK_IDX ] = CharOperation . NO_CHAR_CHAR ; } System . arraycopy ( this . levelTags [ JavadocTagConstants . INLINE_IDX ] , 0 , ( possibleTags [ JavadocTagConstants . INLINE_IDX ] = new char [ this . levelTagsLength [ JavadocTagConstants . INLINE_IDX ] ] [ ] ) , 0 , this . levelTagsLength [ JavadocTagConstants . INLINE_IDX ] ) ; if ( ( prefix == null ) || ( ( prefix . length ) == 0 ) ) return possibleTags ; int kinds = levelTags . length ; for ( int k = 0 ; k < kinds ; k ++ ) { int length = possibleTags [ k ] . length ; int size = 0 ; int [ ] indexes = new int [ length ] ; for ( int i = 0 ; i < length ; i ++ ) { <START_BUG> if ( CharOperation . prefixEquals ( prefix , possibleTags [ k ] [ i ] ) ) { <END_BUG> indexes [ ( size ++ ) ] = i ; } } char [ ] [ ] tags = new char [ size ] [ ] ; for ( int i = 0 ; i < size ; i ++ ) { tags [ i ] = possibleTags [ k ] [ indexes [ i ] ] ; } possibleTags [ k ] = tags ; } return possibleTags ; } private CompletionJavadoc getCompletionJavadoc ( ) { } private CompletionParser getCompletionParser ( ) { } private void initLevelTags ( ) { } protected Object parseArguments ( Object receiver ) throws InvalidInputException { } protected boolean parseParam ( ) throws InvalidInputException { } protected boolean parseReference ( ) throws InvalidInputException { } protected boolean parseTag ( int previousPosition ) throws InvalidInputException { } protected boolean parseThrows ( ) { } protected boolean pushParamName ( boolean isTypeParam ) { } protected void pushText ( int start , int end ) { } protected int readToken ( ) throws InvalidInputException { } protected Object syntaxRecoverQualifiedName ( int primitiveToken ) throws InvalidInputException { } protected Object syntaxRecoverArgumentType ( Object receiver , List arguments , Object argument ) throws InvalidInputException { } protected Object syntaxRecoverEmptyArgumentType ( Object methodRef ) throws InvalidInputException { } protected void updateDocComment ( ) { } protected boolean verifySpaceOrEndComment ( ) { } }

Fix:
if ( CharOperation . prefixEquals ( prefix , possibleTags [ k ] [ i ] , false ) ) {